Selective signaling system.



J. McPELL. SELECTIVE SIGNALING SYSTEM.

APPLICATION FILED MAY 17, 1909.

Patented Jun 18, 1912.

4 SHEBTSSHEET 1.

J. MOFELL.

SELECTIVE SIGNALING SYSTEM.

AYPLIOATION FILED MAY 17, 1909.

Patented June 18, 1912.

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SELECTIVE SIGNALING SYSTEM.

APPLICATION FILED KAY 17, 1909. 1,030,197. Patented June 18,191-2.-

4 SHEETS-SHEET 3.

COLUMBIA PLANOGRAPH CO.. WASHINGTON. C-

Ina/a J. MOFELL. SELECTIVE SIGNALING SYSTEM. APPLIOATION IILED MAY 17, 1909.

1,030,197, Patented June-18, 1912.

4 SHEET8SHEET 4.

a flpirzes 6 co JUDSON MGFELL, OF CHICAGO, ILLINOIS.

SELECTIVE SIGNALING SYSTEM.

Specification of Letters Patent.

Patented June 18, 1912.

Application filed May 17, 1909. Serial No. 496,522.

To all whom it may concern Be it known that I, JUDsoN MoFELL, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Selective Signaling Systems, of which the following is a specification.

My invention relates to selective signaling systems and has for its salient object to provide a single wire, common battery selective system by which any station may call any other.

My invent-ion has further for its object generally to provide an efiicient and reliable signaling system, and specific aims and advantages of my invention may most readily be understood from the following description of the construction and operation of an embodiment thereof, illustrated in the accompanying drawings, wherein- Figure 1 is a schematic view of circuit connections of the devices embodying my invention; Figs. 2, 3, and l illustrate in detail a form of signal initiating device, suitable for the practice of my invention; Fig. 5 is an enlarged detail of'a selector. construction and associated devices suitable for the practice of my invention, with partial schematic circuit connections suggesting the electric association of the parts. Fig. 6 is a representation of an appropriate form of pole changer for use in connection with my system; and Fig. 7 is another, simpler view of the circuit.

In the embodiment of my invention herein shown, I provide a single line 10, preferably grounded at both ends, or otherwise connected for completion'of a series circuit, provided with asingle source of current supply, such as a battery 11, and having arranged along the line any suitable number of stations A, B, C, and D, (all of which may be in the details of equip' ment exactly like the station A and a pole changing equipment A at some suitable point anywhere along the line, where the battery 11 may happen to be located. At each signaling station there is a selectively operable signal initiator in the form of a line breaking switch for interrupting the line to send a plurality of impulse groups constituting number signals, and also suitable signal responsive devices, two or more in number adapted for successive operathe pole changer suitably timed in respect to'the operation of the signal initiating devices, so that operations of the pole changer to change the polarity of the line and the signaling operations of the signal initiator 7 take place in predetermined sequence. That is to say, the pole changing devices and the signal initiating devices are so related in time of operation that the line will be of i one polarity at the time of one signal initiating operation'or the transmission of one group of impulses and of another polarity at thetime of another signal initiating operation or transmission'o'f' another group of impulses. And at the several signaling stations the responsive devices are so related to the line, through the agency of polarized relays, that one signal responsive device will be conditioned for responsive operation only when the line circuit is broken and made while exhibiting one polarity, and

another responsive device will be conditioned for operation only while the line exhibits another polarity, so that predetermined successive signaling operations, coordinate with appropriate polarity changes, will result in successive response of the appropriate signal-responsive devices throughout all of the stations on the line. Thus briefly to state the operations to be provided for, the batteryll normally will be connected to impress one polarity upon the line, and the polarized relays at each station willstand in one relation. 'Each signal initiator will comprise suitable devices for interrupting the line circuit to transmit impulses indicative of two number signals, which I will for distinct-ion term the tens signal and the units signal, and each signal responsive device will comprise a units selector and a tens selector. A polarized relay at each station, responding to the normal polarity of the line, will normally maintain the tens selector in operative or responsive condition, and such relay will so v brate 1n response to the group of=l1ne interruptlons constltutlng the tens signal as 'to be instrumental in causing the tens selec tor to respond by movement to such tens signal, so that throughout all the stations, the tens selectors will move to position determined by the signal. Owing to the timed relation between the pole changing devices and the signal initiating devices, after the transmission of the tens signal is completed and before the transmission of the units signal is begun, the pole changer operates to change the polarity of the line, and a polarized relay at each station, responsive to the new condition on the line and governing the condition of the local circuits of the station, acts instrumentally to condition the units selector for operation. Next the units signal is begun and with the interruption of the line the relay devices at each station operate instrumentally in causing a response of thennits selector with the result that, according to the setting of the respon sive devices, some one or more stations of the line may have had their responsive devices or selectors conditioned to indicate a call, as will be hereinafter more fully explained.

The general organization to be provided, then, comprises the line, means for energizing the line with either polarity, and at each station means for initiating different groups of signal impulses, separate means for response to such signals and means responsive to different line-polarity for conditioning the different responsive means for actuation successively in response to their appropriate signal-impulse groups.

To a full understanding of the particular embodiment shown, the construction and particular operation of certain of the mechanical devices employed must be explained, although in many particulars these devices are only suggestive of any appropriate mechanism for the purposes described.

My preferred form of signal initiating device, as shown in Figs. 2, 3, and 4, consists in two motor driven disks or wheels, a tens wheel 13 and a units wheel 13, the shaft 14 for the wheel 13 having mounted thereon an axially sliding handle 15 rotatively adjustable upon the shaft, carrying a toothed sector 16 which may be set in different positions in close contact with the surface of the disk 13 by engagement of the pin 17 in any one of the series of holes 18 in the disk, and locked in such adjusted position by a latch device 19, pivoted upon the disk and mounted in such a way that, in the rotation of the disk, the tail of the latch will strike a trip 20 to unlatch the sector 16 and permit it to be restored to raised position by a spring 21 inclosed in the handle 15. Similar provision is made with respect to the units wheel 13, the same numerals with the exponent prime being used to indi-.

cate like parts upon the last named wheel. The sector 16 maybe rotarily moved within limits prescribed by pins 22 upon the wheel 13, and the teeth are arranged for coaction with a circuit breaking switch 23, while similar pins 22' and a switch 23 are provided for the other wheel. A number dial 2% is arranged upon the cover or casing of the transmitter, and a pointer 25 is provided upon the handle 15 of the tens wheel to sweep over the numbers, the parts being so arranged that as the handle 25 is moved to bring the point into register with any number, a like number of teeth of the selector 16 are moved back of the switch 23, so that when the selector is locked for operative position and the box operated, that number of teeth will pass the switch 23. Similarly the units devices are so equipped that as the pointer 25 is moved to any number of the dial 24, the sector 16 is positioned so that a corresponding number of teeth will have. passed the switch 23 in the operation of the device before the releasing member 20 operates the latch 19 to disable the toothed sector 16' from further operation of the switch. For certain purposes to be described, it is advantageous that the last circuit breaking operation of each of the units and tens wheels shall be prolonged, and so on the tens sector 16 I provide a terminal tooth 16* of greater length than the ordinary signaling teethsay three times the normal length-while on the units disk I provide a tootlrflange 16 located in such position that it will engage the movable member of switch 23 just as the last tooth of those positioned for operation comes into engagement with said movable element of said switch. This flange 16" is likewise longer than the normal tooth, and may preferably be of the same length as the elongated tooth 16 of the tens wheel. Upon the units wheel 13' I also provide a single permanent or stationary tooth 16 which operates, as will hereinafter be described, in connection with the switch 23 to control the release of the selector devices at the several stations. The relation of the teeth hereinbefore described is such that, assuming the wheels 13 and 13' to be rotating synchronously in opposite directions, the teeth of sector 16 on the wheel 13 operate the switch 23 for a series of short breaks and a final longer break, and then, at any desired period later in the revolution of the wheel, the sector 16 is unlatched and spring moved to inoperative or disabled position, the units wheel 13 has its teeth come into operative relation with the switch 23 after the tens wheels has completed its signal, operating switch 93 as many times as there are teeth. set forward of the releasing position, and the sector 16 being released during the time when the switch 23' is opened by the elongated flange tooth 16; and after this time, preferably when the signaling wheels have almost completed their revolutions, the fixed tooth 16 on the units wheel 13 momentarily opens the switch 23 again. Suitable means are of course provided for driving the wheels, the shafts 14- and 14 being connected by spur gears 24 24*, with which is associated a tilting, spring-pressed stop lever 25*. Motion is imparted to shaft 14 by a spring 26 through suitable gearing, and for speed con trol, a gear train is led to a suitable governor 27. A winding handle 28 is provided in any suitable arrangement to wind up the spring 26, and at the finish of its winding movement, to trip the lever 25*, thereby to free the gears 24 and the Wheels 13 and 13 for operation, to run through one complete revolution before they will stop again. Also I provide a switch 29 in connection with one of the shafts operated by a cam 29 on one of the shafts to shunt the switches 23, 23, whenever the signal initiating device is out of. use or at rest. It will be understood that this particular form of mechanism is illustrated only for purposes of full disclosure and because I regard it as advantageous as a signal initiating mechanism, but it will become obvious that any device capable of operation manually or automatically to cause short breaks in the line indicative of number digits, with the last break elongated in time, and subsequently to cause a single short break incident to the selector releasing operation hereinafter described, might be employed to operate all of the other devices shown in the present system.

At each subscribers stationthere is provided, in the embodiment shown, a local circuit equipment including preferably devices as shown in Fig. 5, comprising a tens selector 3O intended to work in response to the number signals transmitted by the tens wheel 13 and a units selector 31 intended to operate in response to the number signals of the unit wheel 13' and a bell or other signal device controlled by the selectors. The selectors comprise the toothed segments 30 and 31, adapted for step-by-step operation, bearing movable contacts 32 and 32, arranged when the sectors have advanced a certain number of steps to make contact with stationary contact points 33 and 33; and for advancing the sectors, live pawls 34, 34 are provided on opposite ends of a pawl carrier 35, connected by parallel links 36 with the armature 37 of an electro-magnet- 38, the carrier 35 being thereby arranged so that it may be swung to one side or t e other to bring either the dog 34 or the dog 34 into operative relation with the corresponding sector, and to disable the other selector for operation. Each selector is provided with a dead or holding pawl, respectively indicated at 39 and 39', the first named pawl having a long light leaf spring 40, and the latter a shorter stronger spring 40. The pawl 39 is so arranged that when it is in engagement under a tooth of a sector it cannot be directly pulled out of engagementtherewith, but can only be swung out of the path of the teeth as the tooth which it engages moves upward. The pawl 39 has connected therewith a releasing bar 41 extending across in suitable guided fashion to the opposite sector 30, where it is provided with a hook 41 arranged to be engaged by a pin 42 upon the sector 30 when the latter is in lowest or normal position, the arrangement being such that the engagement of pin 42 with hook 41 draws the bar 41 over to hold the pawl 39 out of engagement with the teeth of the sector 31, the engagement of the pawl 39 with the teeth of the sector being such that this with drawal of the pawl may be accomplished at any time. A pin 42 is provided upon the sector 31 so that when the latter is in lowest or normal position it latches the rod or bar 41 in the retracted position described. The bar 41 has such connection, as through a stud 43, with the spring 40 of the holding pawl 39 of the tens selector, that it may buckle the spring in either direction, making it tend normally to hold the pawl 39 in tooth engaging position when the bar 41 is in retracted position, as shown, or to tend to throw the pawl 39 out of tooth engaging position when the bar 41 is advanced by the action of the stronger spring 40 after the pins 42 and 42 have released said bar 41.

For shifting the pawl-carrier 35 into operative relation to one or the other of the sectors 30 and 31, I provide a selector controlling arrangement '50 comprising a pair of opposed magnets 51 and 51 having pivoted therebetween an armature 52, the end of which engages a swinging link 53, pivoted at 54, and provided with a pin 55 engaging a suitable opening in the carrier 35, so that as the armature 52 is swung to one side in response to the attraction of the magnet 51 it throws over the link 53, and the carrier .35, in order that when the carrier subsequently is lifted by the operation of armature 37 of the selector magnet 38, the pawl 34 will serve to advance the selector 30 while the pawl 34 is removed from the selector 31 thereby disabling the latter. Opposite movement of the armature 52 in response to the magnet 51 moves the carrier 35 in the opposite direction to condition the selector 31 for operation and disable the selector 30.

Now, assuming that the parts stand in the position shown in Fig. 5, a series of impulses transmitted through the magnet 38 indicative of a tens digit, will cause the pawl 34 to be successively raised and lowered, advancing the selector 30, At the first step of the selector 30, the pin 42 frees the bar 41, which, however, remains in retracted position 011 account of the engagement of its opposite extremity with the pin 42 upon the yet-stationary sector 31. Consequently, the holding pawl 39, under tension of its spring l0 tending to advance it, operates to hold the sector 30 after each advancing step. If, following this movement of the tens selector 30, magnet 51 is energized, reversing the position of armature 52 and swinging over the pawl carrier 35, and then a group of impulses indicative of a units digit be sent through the selector coil 38, the pawl 34'. advances the sector 31, the first step removing the pin l2 from engagement with the bar ell thereby enabling the pawl 39 to advance into functionally operative position so that it may hold the sector 31 during its several successive steps. This advancement of the pawl 39 carries with it the rod ll which reverses the tension upon the light spring %0 of the holding pawl 39 for the tens selector, which is only prevented from disengaging from the tens selector by the shape of the tooth which it engages. If, following this ope 'ation, the magnet 51 is again energizedthereby conditioning the selector 30 for further operation and disabling the selector 31-and a single impulse is then sent through the magnet 38, both of the selector devices are released tor return to normal position in the following manner: As soon as the pawl 34 advances the sector 30 a portion of a step, the tooth theretofore engaged by the holding pawl 39 moves out of enagement with said holding pawl, which is thereby freed to swing to retracted position under the retracting tension of its spring 40, so that as soon as the impulse through the magnet 38 is over and the armature 37 drops back, the unrestrained sector 30 swings back under the impulse of its spring to normal position, during which operation the pin l2 engages the hook 41 of the bar 4C1, retracting the bar ll and thereby pulling the holding pawl 39 out of engagement with the sector 31, thus enabling the latter to return to initial position so that the parts are all restored to the position shown in Fig. 5.

For certain purposes, which will hereafter become apparent, the armature 52 of the selector controlling magnets 51 and 51' is provided with a switch block 57 arranged for cooperation with switches 58 and 59 on the one side, dominated by magnet 51, and 5S and 59 on the opposite side controlled by magnet 51.

For certain purposes to be described, the selector 80 has associated therewith switches 61 and 62, both maintained opened when the selector is in normal position and arranged to close with the first movement of the tens selector from the normal position, the switch 61 controlling a buzzer 63, and the switch 62 controlling the magnet 65 of a retarding device 64 for a cutout switch. In the specific construction shown, the armature 66 for the magnet 65 is rotatable and has a ratchet-and-pawl connection with a fan-governed speed reducing train 67 in well known fashion, an arm 68 upon the armature 66 operating after suitable time interval determined by the retarding gear, if all the while the magnet 65 is maintained energized, to trip a latch 69 for an armature lever 70 which when released by the latch and spring retracted, holds the latch in elevated position and opens a cutout switch 72. The switch-opening lever or armature 70 is provided with a magnet 73 for restoring it to initial position, and the bell crank latch 69 is associated with a short circuiting switch 7-1 for said magnet to maintain it normally closed while the latch is in operation, but to open the switch when the latch is moved to unlatching position. Further the central station is provided with a bell 76, which, as a refinement convenient of employment, may be controlled by a self-opening switch 77, normally closed by a springpressed lever 78, arranged to be moved to switch-releasing position by a finger 79 on the pawl carrier 35, said finger 79 being thrown into operative relation with the lever 78 only when the selector 31 is conditioned for operation, and the lever 78 being provided with dash pot 80 which permits free operation of the lever by the finger 79 but retards its spring return. Thus, in general, I provide two selectors or responsive devices, controlling a signal bell, independently operable, and arranged to be alternatively conditioned for operation by the controlling magnets 5151' and functionally operated by magnet 38, and, if desired, a retarded cutout switch and a restoring magnet therefor. The controlling magnets are to be themselves controlled by the polarization of the line 10, and so operative instrumentalities and circuit connections for the parts described may be provided as follows: At each station I provide two polarized relays 90 and 90, which I will term the tens and units relays, having their coils in series in line 10 and so related to each other as to polarization or connection of the local circuits that they work oppositely or perform their corresponding functions under opposite conditions of polarity. In the present installation 91 and 91 are the front contacts of the relays and 92 and 92 the back contacts thereof, the relays being wound so that under, say positive, polarity of the line one relay 90, stands with its armature 93 against its front contact, while the other armature 93 stands against its back contact; reversal of polarity reversing the positions of the armatures.

95 indicates a local battery having one terminal-say the positiveconnected by connected by a wire 98 with the selectoroperating magnet 38 and thence by wire 99 through the cutout switch '7 2 to the other pole of the local battery. Thus the operating circuit for magnet 38 is controlled by tens relay 90 when switch 58 is closed, and

by units relay 90 when switch 58 is closed.

The front contacts of both polarized relays have similar connections by wires 100 and 100 through the respective switches 59 and 59 with the respective magnets 51 and 51, the opposite terminals of which are connected in common by wire 101 with the negative terminal of the battery, said wire 101 including the magnet 73 normally shortcircuited by a switch 74. It will be understood that the circuit for the magnet 51 is made only when the armature stands in position to which it is attracted by magnet 51 and vice versa, so that as soon as either of said magnets 51 and 51 receives current through a circuit including a switch and attracts the common armature 52, it cuts itself out of circuit by opening its switch 59 or 59 and conditions the opposite magnet to receive current and correspondingly operate. In general these connect-ions are vall instrumental to secure responsive movement of the selectors to the signaling impulses, provided suitable changes of polarity of the line be effected. Thus, assuming the parts to stand as shown in Fig. 1, with the line polarity positive, if a series of impulses indicative of a tens digit be transmitted by breaking and closing the line, each break in the line, deenergizing the polarized relays 90 and 90, allows the armature 93 which, only, has been held on its front contact, to fly to its back contact 92, thereby closing a battery circuit 95, 96, 97, 98, and 99', which includes the magnet 38 and causes the tens selector to be stepped up the designated number of times. Assuming that during the elongated last break of the circuit in the signaling period for the tens digit, a polarity change occurs in the line. Now, when the line circuit is reestablished, it is the armature 93 of the polarized relay 90, only, which responds by movement to its front contact, and this movement closes a controlling circuit from battery 95, 96, 91, 100, 59, 51, 101, back to battery 95; that is to say, an energized circuit including the selector-controlling magnet 51", which pulls over armature 52, disabling the tens selector and conditioning the unit selector for operation, and at the same time, breaking its own circuit at the switch 59 and closing connection between wires 97 and 98, through the switch 58, so that relay 90 now controls the operating circuit for magnet 38. Now if another group of breaks be effected in the line indicative of the units digit, the vibrations of the armature of the polarized relay 90 make and break an energized circuit 95, 96, 97, 98,'and 99, in-

cluding the selector-operating magnet 38,

the activity of which (through the position of the selector-controlling armature 52 and the consequent positioning of the pawl carrier 35) serves to actuate the units selector 31. Thus, it will be seen that I provide in general as partof each station equipment,

independently operable selector devices 30 and 31, and electro-magnetic operating means therefor in local circuit, controlling meansin the form of magnets 51, 51, and other appliances for conditioning either se lector for operation, and means in the form of the tens and units polarized relays 90 and 90 acting upon the local circuit and responsive to diiferent polarities upon the line to govern the selectorcontrolling devices through a controlling circuit and also responsive to interruptions in the line to actuate the selector-operating means through an operating circuit.

The contacts 33 and 33 for the two sewire 106, back to the negative terminal of the battery. The switch 77 and the dash pot construction 80 are provided simply in order that there may not be given a click of the bell as the selector passes the number of a station which is not the one called, the

dash pot being so timed that it will retard the reclosing of switch 77 for a length of time greater than the interval between two signaling impulses, so that only when the selectors come to rest on the bell contacts 33 and 33 will. the bell circuit be closed through the switch 77 and the bell occasioned to ring. In order that all stations may, however, be apprised when the selector system is in operation, so that no interference will occur,I wire the buzzer 63 and the switch 61 in a connection 107 between wires 103 and 106, so that with the first movement of the tens selector of every station the buzzer circuit for that station is closed by wire 103, buzzer 63, wire 107, and

99 and thereby bridging the selector magnet 38, said wire 108 including the coils of the retarding device 61. In the normal operation of the system, the retarding device performs no effective function. Vith the first signaling impulse, moving the tens selector, it is thrown into the same operating circuit as the operating-magnet 38 but in parallel thereto, so that when, with each break of the line 10, the magnet 38 receives current, the magnet 65 also receives current. lVith each current impulse the magnet (35 begins to attract its armature, the motion of which is so retarded that it advances only a little way during an ordinary signaling impulse and as soon as the circuit is again broken drops back to initial position instantly by reason of its ratchet-and-pawl connection with the retarding train. The period of retardation effected by the train is greater than that of any signaling impulse, even the longer ones, but in the event of accidental break in the line, which, if not safeguarded against, would close the local operating circuit for the selector-operating magnet 38 and run down the local battery 95, the continued energization of the magnet 65 for an abnormal period of time occasions it finally to so operate the train as that its arm 68 operates the latch 69 to release the armature lever 70 which opens the cutout switch 72 of the local operating-circuit. This, of course, also cuts out the retarding relay (35 so that its armature immediately drops back to its normal position. The armature lever 70 controlling the cutout switch 72 remains retracted, however, and holds in unlatched or raised position the latch 69, thereby opening the short-circuiting switch 74-, for magnet 73. On the reclosing of the main circuit, now, current is passed through the magnet 78, as will be hereafter explained, so the armature lever 70 is immediately attracted, the latch 69 permitted to fall into latching position, the magnet 73 short-circuited by the closing of switch 74:, and the cutout switch 72 again closed.

The pole changing devices in general concept consist of a pole changer timed in operation with respect to the signal initiating devices to effect changes of polarity between the respective tens and units signaling operations of the signal initiator. In the present construction, this timing relation is secured by making the final circuit-breaking step of each signaling operation distinctive from the other steps thereof and making the pole changing devices responsive to such distinctive step, but within the broader aspect of my invention, the timed relation may be otherwise secured, as by construction of the signal initiating devices, so that their several operations will occur within arbi trary predetermined time limits and construction of the pole changing devices so that the pole changing functions will occur at arbitrary predetermined periods of time in proper chronological relation with the periodicity of the signal initiator. \Vith respect to the present particular construction, it will be remembered, that each number signal consists of a series of short breaks in the line circuit and a final longer break. The pole changer is a structure for changing the connection of the source of current supply with the line to vary the direction of current flow in the line, functionally nonresponsive to short breaks in the line and functionally responsive to the longer breaks in the line, which mark the termination of the several signaling periods of the signal mitiator.

The specific pole changer construction herein shown is arranged to employ controlling and operating devices very similar to those of a signaling station, there being provided polarized relays 90 and 90", a local battery 95, controlling magnets 51 and 51*, their associated switches 58 and 59 etc., and an operating magnet 38, all arranged in circuit connections precisely like those of the station A and indicated by like numerals of reference differentiated by the exponent a The further equipment of the pole changing devices varying from regular station equipment is as follows: The armature of the operative magnet 38 has a ratchet-and-pawl connection with a retarding train (34 sufficiently retarded to prevent the armature from rising completely in response to the magnet during the interval while the normal teeth are opening the line circuit, but arranged to permit the armature to completely respond to its magnet during the longer interval when an elongated tooth 16 or 16" of the signal initiator is opening the circuit. The armature carries a swinging link 53* connected with the armature 52 common to the magnets 51 and 51 and the link bears an operating bar 35* which, by the movement of the armature 52, is brought into operative relation with one or the other of the two switches 110 and 110. These two switches 110 and 110 are arranged with reference to the bar 35* so that the selected one of them will be closed only by the full movement of the armature of operating magnet 38* to closed position. The two switches are connected in common by wire 112 to wire 99* and have separate connection by wires 113 and 113 through two pole changing magnets 114 and 114, the remote terminals of which are connected in common by wire 115 to the wire 98*, so that when either switch 110 or 110 is closed, it establishes a shunt around the magnet 38 which said shunt includes one or the other of the magnets 114 114 of the pole changer. These two magnets, as best shown in Fig. 6, control by their armatures 116 and 116 two stops 117 and 117 which are arranged to check at diametrically opposite points in its rotation an arm 118 mounted upon a shaft 119 driven preferably by a normally wound mechanical motor 120. The shaft 119 also carries an arm 121 cooperating with rocking lever 123 arranged between two legs 124 and 124 thereof, each said leg being provided with a projection 125, for purposes to be described. The lever 123 pivots upon a pin 126 and beyond said pin has a pair of fingers 127 and 127 embracing a lever 130 pivoted at 131 provided with a shifting spring 132, which tends to pull the arm 130 in either direction according as the point of attachment of the spring is brought to one, or the other side of the pivotal point 131. The lever 130 in its throw to one side or the other of the center, strikes pins 134 and 134 on a switch arm 135 arranged to operate with long tongues of a pole changing switch 136 of well known type of construction.

With reference to Fig. 6 it will be seen that if the latch 117 be tripped, the arm 118 will rotate till it strikes the latch 117 and during the first few degrees of the half rotation thus imparted to the shaft 119, the arm 121 presses the, point 125 sidewise to such an extent that the finger 127 moves lever 130 past its center, so that the spring 132 snaps said lever over into contact with the point 134 throwing the switch 135 and permitting the long tongues of the switch 136 to spring into contact with their back contact points. Before the arm 121 comes to rest it moves the leg 124 of lever 123 to bring the lever 130 nearly to the center line. Upon subsequent tripping of the latch 117 the operation is repeated in reverse d rection to restore the parts to the position shown in Fig. 6. Further for manual circuit breaking operation, a key 140 may be provided at the station where the pole changer is located.

In rsum, the general operation of the system is as follows: If the party at station A desires to call say the station whose selector is set at 45, he sets the tens selector at 4 and the units selector at 5 by turning the respective index hands 25, 25 of his signal initiator or transmitter to such positions and then pushing down upon the handle of each wheel as he sets it, to latch the sectors 16 and 16 in operative position. The setting of the sector 16 at 4 throws four of its teeth back of the breaking switch 23, and the setting of the pointer 25 at 5 throws back the sector 16 of the units wheel so that five of its teeth may pass the switch 23 before the wheel reaches that arbitrary point at which the latch for the sector 16 is tripped. Having thus set the wheels, the calling party pulls down upon the lever 28 to wind the motor for one rotation of the signal wheels, the handle in its operation rocking the lever 25 to release gear 24 and the signaling operation commences. Instantly the cam 29 leaves the switch 29, opening the short circuit normally around i the transmitter switches 23 and 23 and the tens signal initiator commences to break the line circuit at the switch 23. Each time the line circuit is broken, both polarized relays 90 and 90 at every station become energized. The relay 90 at each station standing initially in connection with its back contact and being re sponsive only to the opposite polarity to that which is then impressed upon the line, remains inert, but the relay 90, which is responsive to the polarity then upon the line and so initially stands against its front contact, drops back against its back contact each time the line tircuit is broken, with each such vibration completing the operating circuit heretofore described, and shown in heavy lines in Fig. 1, and sending a number of impulses equal to the signal number through the signal operating magnet 38 at each station. As the selector controlling parts normally stand in the position shown in Fig. 5, each impulsive energization of the magnet 38 results in an advancement one step of the tens selector 30 and the four impulses will advance the selector four steps, the advancement of the selector freeing the bar 41 from the restraint of pin 42 pin 42 holding the bar 41 so that it maintains the spring 40 for the tens-selector holding-pawl 39 in such bearing upon the pawl that said pawl functionally operates to hold the selector 30 in advanced position. At the pole changing station A, these same local circuit affecting operations have been going forward, the magnet 38 being energized at each circuit closing operation, but the duration of the circuit closure being too short to enable the magnet to pull its armature home against the retarding effect of the train 64. But the last toot-h of the tens signal initiating sector 16 being elongated, it retains the line circuit in open condition longer than the normal opening of one tooth, and during this abnormally long opening the magnet 38 at the pole changer station receives current for sufiicient length of time to enable it to overcome the retarding effect of the train 64 and to pull its armature clear home, thereby closing the switch 110. This closure of the switch 110 establishes a local pole changer circuit as follows; (it being remembered that the circuit is closed at the polarized relay 90): battery 95 wires 96*, 97?, 98 115, pole'changer magnet 114, wire 113, switch 110, and wires 112, 99 back to the battery 95 Consequently, during this elongated opening of the circuit, the magnet 114 of the pole changer (see Fig. 6) is energized and trips the latch 117 permitting a halt rotation of the shaft 119 and a consequent operation of the pole changer in the manner described to reverse the connection of the battery 11 with the line. Therefore, when the elongated tooth 16 of the tens wheel completes its passage of the switch 23 and the line is again closed, it exhibits the opposite polarity from that which was initially impressed thereon, and consequently, the armatures of the relay 90 and the relay 90 do not respond by leaving their back eontacts, but the armatures of the units relays 90' and the relay 90 do leave their back contacts and fly over to their front contacts. At each station, therefore, a controlling circuit is closed respectively from the battery 95, by wire 90, 100, switch 59, magnet 51, and wire 101 and from battery 95*, by wire 96, 100, switch 59 magnet 51, and wire 101, energizing the controlling magnets 51 and 5F and causing them to throw over the armatures and 52 thereby to throw over their respective bars 05 and 35, so that at each station the tens selector is disabled while the units selector is conditioned for operation and brought under control of the relay 90, while at the pole changer station, the switch 110 is disabled and the switch 110 conditioned for operation under control of relay 90 These effects of the change of pole are manifested almost instantaneously, and before the units initiator begins to break the circuit. The units wheel 13 ot' the signal initiator, now coming into operation, opens the switch 23 five times causing the armatures of the magnets of the units polarized relays 90 and 90*" to vibrate tive times, in each vibration closing circuits 90, 97, SS, 98, and 99, and 96. 97 58 98 and 99 thereby with each vibration to energize the magnet 38 or 38 and at the several signaling stations to cause the operation of the units selector 31.

Just as the last tooth set for operation 011 the units signal initiator comes into operative relation to the switch 23, the permanent elongated contact 10 opens the switch 23 and holds it open for a longer period of time than that of an ordinary signaling operation, during which period the latch 19 is tripped by the point 20, thus permitting the toothed sector to rise out of operative position. This elongated opening of the circuit enables the magnet 38 at the pole changing station A again to receive current. for a sutiiciently long time to overcome the operation of its retard train 0 1 thereby to close the switch 110 and energize the magnet 111 through the circuit 95 96, 97 58 31141111, 113, 110, 112, 99 back to the battery. Consequently a second pole changing operation occurs and the positive polarity originally existent upon the line is restored thereto, so that when the elongated circuit breaking tooth 16 of the units wheel passes the switch 23 the tens polarized relays 90 and 90 respond, closing the circuits of the controlling magnets 51 and 51, which occasion the throwingover to original position of the armatures 5'2 and 52 and the restoration of the tens selectors 30 at the signaling stations and the switch 110 at the pole changing station to operative association with magnets respectively 38 and 38. At all of the stations along the line, the tens and units selectors now stand with their movable contacts respectively at the fourth position and the fifth position, but only at the station 45 will the stationary contacts 33 and 33 be located in these positions. At this station, therefore, when the final contact was made on the units selector, a circuit is established for the bell 76 from the positive pole of the local battery by wire 103, through the bell 76, wire 101, switch 77, contact 33, the two movable contacts of the selector and their connection 105, the contact 3", and wire 106 back to the battery, so that, as long as the selectors remain in set position, the bell will ring at the designated station. This condition endures until near the completion of the rotation of the signal initiating wheels, when the permanent tooth 16, on one of the wheels, comes into circuit opening position and effects a short quick opening of the circuit, causing a momentary closure of the local operating circuit at each station, as indicated by heavy lines in Fig. 1, and thereby causing each tens selector 30 to be stepped up one notch farther, but as soon as the impulse is over, both selectors will drop back to initial or normal position because, it must be remembered, the movement of the bar 41 accompanying the first step of the units selector has previously buckled the spring 40 reversely, so that itwill act to pull the holding pawl 39 away from the tens selector 30 as soon as the upward step of said selector commences, and so when the live pawl 31 drops, the sector 30 returns to initial position and the ringing ceases. The engagement of the pin 42 with the rod all on its descent, retracting said rod and the holding pawl 39' of the units selector, enables the units selector to return to the initial position shown in Fig. 5, so that the selective devices are all normal again. At the pole changer station, this single short impulse is insuflicient to operate the pole changer, so that under the conditions described the entire systcm stands again in the condition shown in Fig. 1 with all parts normal.

The only function of the retarding device (34, described heretofore, at each station is to prevent exhaustion of the battery 95 through a long closure of the local circuit due to a breakage of the main line 10. It has been explained that as soon as the tens number selector 30 moves away from its normal position, it permits the closure of switch 62 and accordingly throws the magnet winding 65 in shunt to operating magnet 38. The retarding effect of the train 67 is such that during the closure of the operating circuit, including magnet 65, occasioned by any normal signaling break in the line 10, the latch 69 will not be operated or released, but if the line wire 10 becomes accidentally broken so that the local operatingcircuit is closed during a considerable interval of time, the armature 66 of magnet 65 reaches home and its arm 68 operates the latch 69 releasing the armature lever 70 which opens the cutout switch 72 of said opera-tin circuit. This movement of the latch69 is ac companied by an opening of switch 7 1 which thereby throws into servicewire 101 the restoration magnet 7 3. This magnet gets no current until the line circuit is again closed, and then it gets current because when the line does close, it closes with a negative polarity impressed thereon the opposite from that Whichprevailed originallyowing to the factthat the long break in the line has resulted in the operation of the pole changer, just as it would if the break were occasioned by a long tooth of the signal initiator. Now when the units polarized relay 90 responds to the change of polarity upon repair of the break in the circuit, current flows through the controlling circuit from the battery 95, through wire 96, front contact 91, through wire 100, switch .59, controlling magnet 51, and wire 101 back'to battery so energizing the magnet 73, which pulls over its armature 7 0, closing the cutout switch 72, and leaving the whole system in the same condition that it would be in had the tens element of the signal initiator been operated to send simply the 1. To restore the system to initial condition with all its devices in proper step and the proper polarity upon theline, the line circuit should be broken, as at switch 140, for a period equal to the duration of passage of several teeth and then again for an instantaneous period such as that of the passage of a single tooth, there by stepping up each units selector one point to free the bar 11 and to causea pole change to occur back to normal polarity of the line, and thereafter to release the selector devices without causing a pole change on the line.

It will be apparent that the devices described constitute only one means of effect-- ing the operations desired, and that many variations might be made in-the apparatus and connections without departure from the spirit of my invention.

hat I claim is: Y

1. In a selective signaling system, a line; means for energizing said line with either polarity; and, at each station, means for initiating signals on the line, a plurality of signal responsive means, and polarized means controlling the signal -'responsive means for operation according to the line polarity to condition certain signal-responsive means for operation in response to sig nals initiated in the line, and to disable other signal-responsive means for operation in response to such signals. p

2. In a selective signaling system, a line; a single source of current supply, a pole changer therefor; at each station, a signal initiating switch, a plurality of signal-responsive means, and means for alternatively conditioning different signal-responsive devices for operation and disabling other signal-responsive devices under each polarity condition of the line.

3. In a selective signaling system, a line; means for energizing the line; pole changing means; and, at each station, means for initiating a plurality of impulse-group signals, a plurality of signal-responsive means, and means responsive to the polarity of the line for conditioning different ones of said signal-responsive means for operation in response to signals initiated in the line, the signal-initiating and pole-changing means being relatively timed in operation to change the polarity of the line during the intervals between dilferent signaling operations thereby to insure response from different signalresponsive means to the difiierent impulse groups occasioned by the signal initiator.

4:; In a selective signaling system, a line; a single energizing means for said line; pole changing means for varying the polarity of the line; at each station, a signal initiator for transmitting in succession a plurality of impulse groups, a plurality of signal-impulse-responsive devices adapted for response to different impulse groups transmitted by the signal initiator, and polarized means, responsive to the line polarity conditions, for conditioning different responsive devices at each station for operation under different line polarities, the signal-initiating devices and the pole-changing means being timed to operate in appropriate relation to each other to secure the conditioning of cer tain responsive devices at each station to respond to different groups of impulses transmitted by the signal initiator.

5. In a selective signaling system, a line circuit common to a plurality of stations;

local circuit connections for each station; means of current supply for the line; independent means of current supply for the several local circuits; pole changing means connected with the source of current supply of the line; a circuit-controlling signal initiator at each station; different signal-responsive devices at each station; and means, at each station, including polarized devices responsive to the polarity of the line to condition for operation different signal-responsive devices under different polarity conditions, and responsive to changes in continuity of the line circuit to efl'ect the operation of the properly conditioned signal-responsive devices.

6. In a selective signaling system, a line circuit; a source of current supply therefor; and means for changing the relation of the source of current supply to the circuit to change the polarity on the circuit; there being a plurality of stations on the line, and at each station, a circuit-controlling signalinitiating switch, and polarized-relay means in series in the line, local circuit connections, local current-supply means, independently operable signal-responsive devices, and electro-responsive means controlled by the polarized-relay means in the line, for conditioning different signal-responsive means for operation according to the polarity of the line and for operating said selective signalresponsive devices in response to the operation of the circuit-controlling switches in the line.

7. In a selective signaling system, a line circuit; a source of current supply therefor; a pole changer for the source of current supply; means for operating said pole changer, responsive to predetermined operations of a signal-initiating switch; there being a plurality of stations on the line, and at each station, a signal-initiating line-controlling switch, local circuit connections, a source of current supply therefor, independently operable signal-responsive devices, and means for conditioning said different responsive devices for operation in response to different polarities in the line, and for causing the operatively-conditioned responsive devices to operate in response to the action of the line controlling switch.

8. In a selective signaling system, a line circuit, a source of current supply therefor, and a pole changing means; there being a plurality of stations on said line, and at each station, two polarized relays in series in the line, a circuit-controlling signalinitiating switch, two selectors independently operable, a local signal device responsive to the operation of said selectors, responsive means for operating said selectors arranged for control by the vibrations of the polarized relays, and selector-controlling means for conditioning one selector for operation and disabling the other, governed by the polarized relays.

9. In a selective signaling system, a line circuit, a single source of current supply therefor, a pole changing means, said line circuit having associated therewith instrumentalities for individual stations; and at each station, two polarized relays operatively associated with the line, a local operating circuit controlled by both polarized relays, a local controlling circuit, local means of current supply for said circuits, a plurality of independent selectors, means for operating said selectors, and means in the controlling circuit responsive to the polarized relays for conditioning different selectors alternatively for operation under control of the polarized relays.

10. In a selective signaling system, the combination with a line; a source of current supply therefor; and a pole changing means; of signaling station apparatus, each station apparatus including two polarized relays in series in the line; a circuit-controlling signal-initiating switch; two independently operable selectors; a local controlling circuit having two branches controlled by the respective polarized relays; an operating circuit, means of current supply for the local circuits; selector-operating means in the operating circuit; and selectorcontrolling means in the controlling circuit, arranged alternatively to condition one or the other of the two selectors for operation in response to vibrations of the corresponding polarized relays, and to condition itself for reversing operation to produce the alternative arrangement in response to vibration of the remaining polarized relay.

11. In a selective signaling system, a line circuit; a source of current supply therefor; a pole-changing means; and at each of a plurality of stations signal-initiating means in the line, a plurality of signal-responsive selectors, electro-responsive means for operating said signal selectors, and controlling means -for conditioning the different selectors for operation and disabling others alternatively, and means for controlling the operation of said controlling means in harmony with the polarity of the line, and actuating the selector-operating means in response to changes in the energization of the line.

12. In a selective signaling system, a line; a source of current supply for the line; and a pole changer therefor; there being associated with the line the apparatus for a plurality of stations, each station apparatus comprising a line circuit breaker, two selectors independently operable, two polarized relays for the respective selectors, having their windings in the line and arranged to act oppositely under different polarities of the line, electro-responsive operating means for the selectors, an operating circuit therefor comprising parallel. branches controlled by the respective polarized relays, a circuit opening switch in each such branch, a controlling circuit providing two parallel branches controlled by the respective polarized relays, a switch in each circuit branch, a controlling magnet in each branch of the controlling circuit, means of current supply for the local circuits,'and means operable by the controlling magnets whereby each controlling magnet acts to close the controlling circuit switch of the opposite controlling magnet, and to close the circuit opening switch in one branch of the operating circuit thereby to condition one se- 'lector for operation in response to vibrations of the armature of the polarized relay controlling said branch of the operating circuit.

13. In a selective signaling system, a line for a plurality of stations, a common source of currentsupply therefor, signal-initiating means, a local circuit at each station wholly extraneous to the line, signal-responsive means in said local circuit comprising a plurality of selectors, and means for operating said selectors independently in succession in response to a similar succession of signal-initiator operations in the line.

14. In a selective signaling system, a line, a source of current supply therefor, signalinitiating means, a local circuit wholly extraneous to the l1ne,signal-responsive means in said local circuit comprising a plurality of selectors, and means including relays acted upon by the line circuit and acting in the local circuit for operating said selectors successively in harmony with successive similar signals in the line.

15. In a selective signaling system, a line; a source of current supplytherefor; a signal initiator in the line; and a local station apparatus comprising a local circuit, means for current supply therefor, a relay acted upon by the line and acting in the local circuit normally to open the same, a signalresponsive device in the local circuit, a cutout switch for the local circuit, and means for operating said cutout switch upon the closure of the local circuit for a predetermined continuous period of time.

16.- In a selective signaling system, a line; a source of current supply therefor; a signal initiator in the line; a local station apparatus comprising a local circuit, a means for current supply therefor, a relay acted upon by the line and acting in the local circuit normally to open the same, a signal-responsive device in the local circuit, a cutout switch for the local circuit, and an electro-responsive device in shunt to the signalresponsive device operable upon energization for a predetermined continuous interval to open the cutout switch for the local circuit.

17. In a selective signaling system, a line; a source of current supply therefor; a signal initiator in the line; and a local station apparatus comprising a local circuit, a means for current supply therefor, a relay acted upon by the line and acting in the local circuit normally to open the same, a signalresponsive device in the local circuit, a cuttion upon the restoration of the main line to normal condition.

18. In a selective signalmg system, a lme; a source of current supply for the line; and

a pole changer therefor; apparatus at each station on the line comprising a line circuit breaker, two selectors independently operable, a common electromagnetic operating means for said selectors, shiftable parts for conditioning either selector for operation by said magnet, electro-magnetic controlling means for shifting said shiftable parts, local circuit connections for said electro-magnetic operatingand controlling means, and means whereby the operation of the controlling-means is governed by the polarity of the line and of the operating-means by the continuity of the line.

19. In a selective signalingsystem, a line; a source of current supply therefor; a pole changer for connecting said source of supply with the line; and at each station a linecircuit-breaking signal initiator, a plurality of independently operable selectors, electroresponsive controlling-means for conditioning the signal-responsive devices successively for operation, electro-responsive operating-means for the signal-responsive devices, local circuit connections for the elect-ro-responsive controllingand operating means, and means whereby the electro-responsive controlling-means operate in harmony with the polarity of the line and the electro-responsive operating-means operate in harmony with the breaking of the line circuit.

20. In a selective signaling system, a single line; a source of current supply therefor; a pole changer; means for operating said pole changer in'timed relation to the signal initiator; at each station a line-breaking signal initiator adapted for predetermined successive signaling operations, a plurality of signal-responsive selectors adapted for successive responsive operations harmonizing with the successive signaling operations, and meansresponsive to changes of polarity in the line for conditioning appropriate selectors for operation and responsive to signals initiated in the line to actuate said appropriate selector.

21. In a selective signaling system, a line circuit, a source of current supply therefor,

to the polarity of the line for conditioning In testimony whereof I hereunto set my different ones of said signal-responsive hand in the presence of two witnesses. means for operation lIl response to signals initiated in the line said means being re- JUDSON MCFLLL' sponsive to signals initiated in the line to In the presence of occasion the operatlon of said signa1-resp0n- W. LINN ALLEN,

sive means. MARY F. ALLEN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of 2mm, Washington, D. C." 

